Protective packaging structures are often used when an article to be transported requires protection from physical shock, dust, dirt and other contaminants. For or example, when shipping articles which may be relatively fragile, it is often desirable to package the article inside a box to protect the article from physical impacts to the box which may occur during loading, transit and unloading. In addition, when shipping sensitive electronic articles, such as computer components, it is often desirable to protect those components from dust and dirt. Aside from the shipping box itself, some additional structures are ordinarily needed to prevent the article from being damaged by uncontrolled movement within the box. Such additional structures have included paper or plastic dunnage, molded plastic foams and foam-filled cushions, among others.
One useful form of packaging for especially fragile articles is frequently referred to as suspension packaging, examples of which are disclosed in U.S. Pat. No. 4,852,743 to Louis H. Ridgeway and U.S. Pat. No. 5,388,701 to Devin C. Ridgeway. In suspension packaging, the article is suspended between two confronting sheets of plastic film. The sheets are usually attached to frames which are sized to fit securely within a selected size box. The frame includes side and end legs which may be folded away from the film so as to space the film from the top or bottom of the box. The fact that the article is not in contact with any substantially rigid surfaces protects it from physical shock.
An alternative to suspension packaging is often referred to as retention packaging. One version of retention packaging utilizes a frame including a rigid border extending around the entire periphery of a window opening, and side legs and end legs foldably connected to and supporting the border. A flexible film is connected to the underside of the border so that it extends across the window opening. An article to be packaged is placed on the film, and a series of four flaps connected to the four sides of the border are folded over the article to hold the article in place against the film. In a variant of this package, disclosed in U.S. Pat. No. 5,893,462 to Devin C. Ridgeway, the rigid border is eliminated, the flexible film is connected to the folding side legs, and only two flaps are foldably connected to the side legs to hold the article in place against the film. This variant provides increased structural rigidity while reducing the overall size of the package.
All of the foregoing packaging structures require side legs and end legs to be folded away from the film for the purpose of supporting the film at a position spaced from the top and bottom of the box. This is a time-consuming and cumbersome process which, when packaging many thousands of articles, may have a substantial impact on employee fatigue and overall shipping costs.
There therefore exists a need for packaging structures which are easier and less time consuming to form than prior art packaging structures. Preferably, such structures will have an efficient design enabling the structures to be shipped in a flat configuration and readily converted to a folded configuration without sacrificing the strength of the packaging structure so as to risk damage to the articles packaged therein.